Expanded metal.



No. 892,938. PATENTED JULY '7, 1908. F. H. GRITTALL. EXPANDED METAL.

APPLICATION FILED APR. 7,1908.

" unbent and therefore not in any way sub- FRANCIS HENRY ORITTALL, OF BRAINTREE, ENGLAND.

EXPANDED METAL.

Specification of Letters Patent Original application filed February 17, 1908, Serial No. 416,233.

Serial No. 425,717.

Patented July 7, 1908.

Divided and this application filed April 7, 1908.

To all whom it may concern:

- Be it known that I, FRANCIS HENRY CRIT- TALL, a subject of the King of Great Britain,

' residing at Manor Works, Braintree, in the county of Essex, England, engineer, have invented new and useful Expanded Metal, of

Which-the following is a specification.

Expandedmetal as commonly made consists of longitudinal zig-zag strips connected together by junctions of twice the width of each strip. According to this invention these junctions are turned in a novel way out of the lane of the sheet and the strips ber served, are substantially square.

' heet.

tween t em are helically twisted in the manner hereinafter described.

Fi ure 1 is a plan of a sheet of expanded meta constructed according to this invention.. Fi s. 2, 3, and 4 are sections respectively on ines 2-2, 3- 3 and 44 of Fig. 1.

A a a are longitudinal zig-z'ag stri s and b b are similar longitudinal strips a ternating with them. The transverse rows of junctions between these strips are lettered c and d alternately. It will be observed that all the strips d are situated above the plane of the sheet and all thestrips 1) below it. Also that all the junctions c are turned anti-clockwise (Fig. 2) out of the plane of the sheet while all the junctions d are turned clockwise, the junctions themselves remaining practically stantially weakened. Again it will be seen that the portions of the strips 0 and b between any' row 0 of junctions and the row (1 next beyond it (Fig. 1) are twisted heliortions of and the row 0 next above it are twisted helically in the o posite direction.

In Fi 4 have shown clearly how the strips a lie above the plane of the expanded sheet. This is also shown in Fig. 3 but this eculiarity is more pronounced near the v unctions c where the section of Fig. 4 is taken.

The meshes of the fabric, it will be ob- In this way the maximum area from a given amount of metal is obtained and yet this is done without weakening'the junctions while the helical twisting of the strips provide an efficient key to the plaster supported by the This ap lication is a division of my appliati on for atent No. 416,233, filed February 17, 1908, which claims the process of roducing the ex anded metal herein claime The machine 'or producing this expanded metal is claimed in my application for Patent No. 416, 234, filed February 17, 1908.

What I claim is 1. Expanded metal in which the strips forming the sides of the meshes are twisted helically, the strips on opposite sides of each mesh bein on opposite sides of the plane of the ex an ed sheet.

2. xpanded metal in which the strips between the slits are situated alternately on the two sides of the plane of the expanded sheet, the junctions between the strips being at an angle to that plane and the portions of each strip between adja cent junctions being twisted helically.

3. Expanded metal consisting of longitudinal zig-zag strips-connected by transverse rows of junctions, all the junctions in one transverse row being turned in one direction to project from opposite sides of the sheet and all the junctions in the two adjacent transverse rows being turned in the reverse direction to project from opposite sides of the sheet.

4. Expanded metal consisting of longitudinal zig-zag strips connected by transverse rows of junctions, the portions of the strips between two adjacent transverse rows of junctions bein all helically twisted in one direction and a l the adjacent portions of the strips being helically twisted in the opposite direction. I

5. Expanded metal consisting of longitudinal zig-zag strips connected by transverse rows of junctions, all the 'unctions in one transverse row being turne out of the plane of the sheet in one direction and all the j unctions in the two adj acent transverse rows being turned out of the plane of the sheet in the reverse direction and the portions of the two adjacent transverse rows being turned out of the v 7. Expanded metal consisting of longitudinal zig-zag strips connected by transverse.

rows of junctions, the strips being situated alternately on the two sides of the lane of the sheet, the portions of the strips etween two adjacent transverse rows of junctions' being all helically twisted in one direction and all the adjacent (portions of the strips beplane of the sheet in the reverse; direction.

alternately on the two sides of the plane of the sheet, all the junctions in one transverse row being turned out of the plane of the sheet in one irection and all thejunctions in the two adjacent transverse rows being turned out of the plane of the sheet in the reverse direction and the portions of the strips between two adj acent-transverse rows of junctions bein all helically twistedin one direction and afi the adjacent portions of the strips being helically twisted in the oppositedirection.

FRANCIS HENRY, CRITTALL 'Witnesses:

F. L. RAND, R. F. WILLIAMS. 

